Reproduction process



United States Patent 3,444,809 REPRODUCTION PROCESS Kinji Ohkubo and Junpei Noguchi, Kanagawa, Japan, as.

signors to Fuji Shashin Film Kabushiki Kaisha, Kauagawa, Japan, a corporation of Japan No Drawing. Filed June 3, 1966, Ser. No. 555,005 Claims priority, application Japan, June 5, 1965, 40/ 32,943 Int. Cl. B41m 7/00 US. Cl. 101-470 9 Claims ABSTRACT OF THE DISCLOSURE Reproduction of an original onto a large number of copy sheets by forming on a support an oil latent image which is a reflected image of the original. This oil latent image is developed with a thermoadhesive powder. The thermoadhesive powder image is then heated and transferred to an image receiving sheet where it is developed by a developing powder.

The present invention relates generally to a reproduction process an more particularly to a process for reproducing an original onto a large number of usual papers or others.

According to the process of this invention, an oil latent image which is a reflected image of an original to be reproduced is formed on an intermediate original sheet, the latent image is developed by the powders of a transferable material having in the temperature range from 70 C. to 170 C., a tackifying point at which it becomes adhesive and remains adhesive when reduced in temperature below its tackifying point and being transferable to an image-receiving sheet such as a usual paper or a film, and then the thus transferred image is subjected to powder development and fixing.

An object of the present invention is to ensure that reproduction has good stability and is not discolored and changed in quality during preservation diflerent from unstable reproduction obtained from a usual silver salt type reproducing element.

Another object of the present invention is to ensure that the above-mentioned transferring procedure can be conducted as many as twenty times and from one intermediate original sheet a large number of reproductions can be obtained.

A further object of the present invention is to enable the whole reproducing process to be carried out by dry system.

Other objects will become apparent from the ensuing specification, as follows:

1. Intermediate sheet As the process for forming an oil latent image on an intermediate sheet, various known processes may be used in this invention, for example;

(1) A process of conducting relief printing using an oil or an oily ink.

(2) A process of typewriting on an intermediate original sheet using a typewriter ribbon impregnated with a large quantity of an oil.

(3) A process of forming an oil latent image of the reflected image of an original on an intermediate sheet by placing on the original to be reproduced a transparent or translucent intermediate sheet coated with an oil having a low boiling point and irradiating infrared rays on to them whereby the oil at the areas corresponding to the black areas or characters of the original is evaporated by utilizing the rapid temperature increase at the areas and transferred to the intermediate sheet.

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(4) A process .of forming an oil latent image by inserting an oil-impregnated paper between an original to be reproduced and an intermediate sheet and then transferring the oil by utilizing the evaporation of the oil as in process (3).

(5) A process of using an intermediate sheet coated with fine pressure rupturable capsules or heat-rupturable capsules prepared by covering an oil with a high molecular material, whereby when the pressure rupturable capsules are used, desired characters are written by hand or by means of a typewriter on the surface to break the capsule by pressure and to form the oil images corresponding to the characters on the surface, or when the heat ruptura-ble capsules are used, the capsules are broken by heat by the irradiation of infrared rays to form an oil image.

It is apparent that other methods for forming oil latent images on an intermediate sheet may be also utilized.

Since the oil latent image in this invention must be the reflected image of an original to be reproduced, in the case of utilizing process (1) or process (2) as mentioned above, specific types or typewritter is used, or a copy obtained by using usual types or typewriter and having characters of printing ink or an oil from a typewriter ribbon is placed on other sheet and the assembly is heated to transfer the printing ink or the oil to the sheet, whereby an oil latent sheet of the reflected image of the original is obtained, which is used as the intermediate.

The intermediate sheet may be used papers, films or metal plates. The oil used for forming latent images may be vegetable oils, animal oils, mineral oils or other oily materials having suitable properties corresponding to the process adopted for forming latent images. Suitable vegetable oils are peanut oil, linseed oil, soybean oil, castor oil, maize oil and tung oil. Typical examples of the animal oils are whale oil, codliver oil and lard oil. Typical examples of the mineral oils are petroleum oil and the fractions thereof, such as, kerosene, naphtha and paratfin oil.

Other oily materials include phosphoric acid esters, such as tributyl phosphate, tri-Z-ethylhexyl phosphate, and the like; phthalic acid esters such as methyl phthalate, butyl phthalate, Z-ethylhexyl phthalate, and the like; and other liquid plasticizers such as adipic acid esters, azelaic acid esters, sebacic acid esters, and glycerine esters. These oils must have, however, such viscosity or stickiness as attaching effectively the below-stating developing powders.

II. Powdered developer for developing the intermediate original sheet having oil latent images thereon The powdered developer for developing the intermediate original sheet described in above Section I has the below-stating good tackiness in the solid powder state to the aforementioned oil and at the same has the following properties.

That is, the powdered developer has such properties that it has no tackiness at normal temperature to a powdered developer to be used in the below-stating developing process for the image-transferred sheet butbecomes adhesive at a temperature range of 70 C. to C. and remain adhesive when reduced in temperature below said temperature for several minutes to several tens minutes. This material is called thermoadhesive in this specification, and these properties also thermoadhesive properties.

These properties are necessary for transferring the oil latent images from the intermediate sheet. Examples of these materials are benzoic acid, sebacic acid, phthalic anhydride, cinnamic acid, maleic anhydride, benzotriazole, p-dimethylamino-benzaldehyde, benzoin, dextrose, l-phenyl-3-pyrazolidone, sorbitol, benzylarnine, tribenzylamine, phenacetin, acetanilide, vanilline, methyldroquinone, 2-4 dihydroxybenzopophenone, B-naphthol and the like. These materials are ground into 0.1 to 100 microns in diameter when used as the powdered developer for the oil latent imags on the intermediate sheet.

The powdered developer may be mixed with an infrared ray absorber. The amount of the infrared ray absorber may be 0.1 part by weight to 1 part by weight of the transferring material. The infrared ray absorber may be organic or inorganic pigment powders. Typical examples of these are carbon black, iron oxides, chromium green, ultramarine blue, cobalt blue, indigo and the like. The addition of the infrared ray absorber is convenient in the case of transferring by placing the intermediate sheet on a transferring paper.

Further, in order to control the transferred amount of the thermo-adhesive material onto the transfer sheet in the case of below-stating transferring process, the abovementioned thermoadhesive material may be mixed with the fine powders of a material having a high melting point, such as metal powders, metal oxide powders or silicon oxide powders.

These mixtures may be prepared as follows: A mixture of 0.1 part by weight of the above-mentioned finely powdered infrared absorber and O-10.0 parts by weight of the above-mentioned finely powdered high-melting point material is thoroughly mixed with 1 part by weight of the above-mentioned thermoadhesive material and then the mixture is melted by heating. After completely solidifying the mixture by cooling, the mixture is finely ground into 0.1-100 microns in diameter by suitable means.

Furthermore, as the powdered developer for developing the oil latent images on the intermediate sheet, there may be used a mixture of fine powders of a material having a good transferable property and a usual toner for electrophotography containing an infrared ray absorber.

III. Transfer from the intermediate sheet When the reflected image of a desired drawing, original or the like, is formed on the intermediate sheet by developing the intermediate sheet having the oil latent image with the above-mentioned powdered developer, it is preferable to once heat the intermediate sheet to melting point of the transferring material by a suitable manner and then cooling to normal temperature. Thus, the developing powder image of the drawing, original and the like, is fixed on the intermediate sheet.

The thus obtained intermediate sheet is placed on an image-receiving sheet after being heated or heated after being placed on an image-receiving sheet. The image-receiving sheet may be a paper but if necessary a synthetic resin film, a metal plate or a cloth may be used. The heating may be conducted by inserting the intermediate sheet or an assembly of the intermediate sheet and the image-receiving sheet between heating plates or may be conducted by infrared heating. In any cases of heating, the transferable material in the powdered developer is transferred from the intermediate sheet to the image-receiving sheet. Usually, a part of the transferable material is transferred from the surface layer to the image-receiving sheet and since the transferable material has a thermoadhesive property as mentioned above, if thus trans ferred image is immediately developed by a powdered developer, the powder is attached to the image portions owing to the tackiness of the transferable material at the image portion to provide an image.

The developing powders used for developing the imagereceiving sheet may be any fine powders of a material capable of being attached to the transferable material in its adhesive state. For example, they may be prepared by dispersing an inorganic pigment such as basic lead carbonate, zinc oxide, titanium dioxide, titanium trioxide, iron oxides, cadmium sulfide, basic potassium chromate, molybdenum orange, cadmium yellow, chromium green, ultramarine blue, and cobalt blue; carbonaceous materials such as carbon black and asphalt powders; or organic pigment such as benzidine yellow, indigo and alizarin in a heat-softenable resin such as phenol-formaldehyde resin, in eutectic mixture of a chlorinated naphthalene and polystyrene, or a copolymer of vinyl chloride and -vinly acetate, and then after being solidified the mixture is granulated into 0.1 to 50 microns by suitable means. A toner which is usually used for electrophotography and electrostatic recording may, of course, be used. The color of the developing powders may be suitably selected according to the color of the support or the image-receiving sheet.

In such a powdered developer, the pigment is dispersed in the hydrophobic resin and in the case where the resin is thermoplastic, the thus developed image may be fixed by heating or by exposure in the vapor of acetone, chloroform, benzene or trichloroethylene.

Moreover, the powdered developer for developing the image-receiving sheet in this invention may be a powdered developer coated with a surface active agent or mixed powders of the powdered developer and the powder of a solid surface active agent. The surface active agent may be one usually used as wetting agent. For example, there are illustrated succinic acid, alkylester sulfonate, alkylbenzene sulfonate, sorbitan alkyl ester, long chain quaternary ammonium salt, polyoxyethylene sorbitanalkyl ester and the like. The amount of the surface active agent may be optionally selected according to the kind of it, but generally about 10 -10 molecules, in particular 10 10 per 1 sq. cm. of the surface area of the powdered developer is preferable.

Such a powdered developer containing the surface active agent has a high attaching power to the transferable material and by using it, the contrast of the image of an original to be reproduced can be increased.

The above-mentioned transfer of the transferable material from the intermediate sheet to the image-receiving sheet can be repeated as many as twenty times about one intermediate original sheet.

Thus, many copies of an original can be obtained on the image-receiving papers.

The present invention will further be illustrated by the following examples:

EXAMPLE 1 An original printed by printing ink containing usual printing ink oil such as linseed oil was placed on usual tracing paper and heated by infrared radiations to transfer the printing ink image to the tracing paper by evaporation.

The thus transferred oil latent image was developed by a developing powder for developing intermediate sheet. The developing powder was prepared by the following procedure:

A homogeneous mixture of 20 g. of the powder of henzoic acid and 1 g. of carbon black was melted by heating to C. After thoroughly stirring the molten mixture, the mixture was solidified by cooling to room temperature and then granular-ted into granules of less than 400 nlileshes to provide the developing powder for intermediate s eet.

After powder development, the tracing paper (i.e. the intermediate sheet) was heated by the irradiation of infrared rays to fix the image and to provide the intermediate (refiected image).

Thereafter by placing the intermediate sheet on an image-receiving paper facing the image surface to the paper after heating said intermediate sheet, or by placing the intermediate sheet on an image-receiving sheet facing the image surface to the paper and then by heating them simply or by heating them from the back of the intermediate sheet by infrared radiations, a part of the transferable material was melted and transferred to the imagereceiving sheet.

Then the image-receiving sheet having the thus transferred latent image was powder developed using the powder developer which had been prepared by melting a mixture of 80 par-ts of polystyrene, parts of phenol-formaldehyde resin, and 10 parts of carbon black and then grinding the solidified mixture into granules of -25 microns in average grain size, and then fixed in a trichloroethylene vapor.

By repeating the procedure, several tens copies were obtained from the one intermediate sheet.

EXAMPLE 2 The oil latent image which had been transferred as in Example 1 to a tracing paper was developed by the powder developer which had been prepared by melting a mixture of g. of vanilline and 1 g. of carbon black by heating to 100 C., solidifying the mixture by cooling to room temperature, and grinding into less than 400 meshes. After fixing this obtained image by the method described in Example 1, the image was transferred to an image-receiving sheet and developed by powder developer as in Example 1. By repeating the procedure, several tens copies were obtained from one intermediate sheet (tracing paper).

EXAMPLE 3 The procedure as in Example 1 was repeated using as a powdered developed for intermediate original sheet the developer which had been prepared by heating a homogeneous mixture of 20 g. of the powder of a plasticizer, Santisizer 9 (made by Monsanto Chemical Co.) and 1 g. of carbon black by heating the mixture to 110 C. and, after cooling, grinding into less than 400 meshes.

EXAMPLE 4 Onto an original was sprayed a 20% acetone solution of dimethylphthalate and the original was placed on a tracing paper followed by exposure in infrared radiations. By adjusting the exposure, the temperature of the areas corresponding to the characters on the original reached the boiling point of the oil whereby the oil at only the areas was evaporatetd and transferred to the tracing paper. Thus transferred latent image on the tracing paper was developed using any one of the powder developer for intermediate sheet in Examples 1, 2 or 3 and thereafter thus developed tracing paper was processed as in Example 1 to provide many copies.

EXAMPLE 5 An original was placed on a tracing paper inserting a thin paper impregnated with glycerine tributylate between them and they are exposed to infrared radiations. The oil at the positions corresponding to the characters of the original was evaporated and transferred to the tracing paper to provide an image, which was developed by any of the powdered developer for intermediate sheet as in Examples 1, 2 or 3. Thus developed tracing paper was processed as in Example 1 to provide many copies.

EXAMPLE 6 Fine capsules of gelatin and gum arabic containing dimethyl phthalate was applied to the surface of a thin paper. Thus prepared paper was inserted between an original and a tracing paper facing the capsule layer to the tracing paper and they were exposed to infrared radiations.

The temperature of the areas corresponding to the characters on the original was increased and the capsules there were broken whereby a latent image of the oily material was formed on the tracing paper. The thus obtained latent image was developed by any of the powdered developer for intermediate original sheet as in Examples 1, 2 and 3 and then the thus developed tracing paper was processed as in Example 1 to provide many copies.

6 EXAMPLE 7 The transferred images of the thermoadhesive material which had been formed on the image-receiving sheets by the methods in Examples 1-5 were developed each using the below-stated powdered developers.

A kneaded mixture of parts by weight of polyester, 10 parts of phenol-formaldehyde resin, and 10 parts of carbon black was ground into granules of 15-25 microns in average grain size. Thus obtained powder developer (10 g.) was added with stirring thoroughly into ml. of a 0.75% aqueous solution of sodium alkylbenzene sulfonate (average chain length of alkyl radical is 12.6) and, after drying in a vacuum, was ground into granules of 88 microns in grain size. (The developer is called Surfactant-treated powdered developer A.)

Or, 10 g. of the same toner was treated with 0.3 ml. of sodium succinic acid di-(Z-ethylhexyl) ester sulfonate by the same procedure as above. After the treatment, the mixture was ground into granules less than 88 microns in grain size. (The developer is called surfactant-treated powdered developer B.)

When the above-prepared developer was used as the developing powder for image-receiving sheet in, for example, the procedure in Example 1, the density of the image was improved as compared with that of the image obtained by using the developing powder without the treatment with the surface active agent as shown in the following table.

In this experiment, the intermediate was prepared by the process as in Example 4 and 1-phenyl-3-pyrazolidone was used as the developer therefor.

Image density Non-treated developer 0.62 Surfactant-treated developer A 1.10 Surfactant-treated developer B 1.25

Manifestly, variations in technique may be envisioned without departing from the spirit or scope of invention as defined in the subjoined claims.

We claim:

1. A process for making reproductions, comprising: forming on a support an oil latent image of an original such that the image is the reflected image of the original,

- developing said latent image with the powders of a thermoadhesive material having in the temperature range 70C.- C., a tackifying point at which it becomes adhesive and adhesive when reduced in temperature below its tackifying point, transferring the thus developed image to an image-receiving sheet by heating, and then subjecting the transferred image on the receiving sheet to powder development.

2. The process for making reproductions as in claim 1, wherein said oil latent image is prepared by relief printing or typewriting.

3. The process for making reproductions as in claim 1, wherein said oil latent image is formed by applying an oil having a low boiling point to an original, placing the oil bearing side on a support, and then exposing same to infrared radiations, whereby the oil is evaporated and the area corresponding to the original is transferred to the support.

4. The process for making reproductions as in claim 1, wherein said oil latent image is formed by inserting a paper impregnated with an oil between an original and a support and exposing same to infrared radiations, whereby the oil is evaporated and the area corresponding to the original is transferred to the support.

5. The process for making reproductions as in claim 1, wherein said oil latent image is formed by utilizing pressure-sensitive or heat-sensitive capsules containing an oil.

6. The process for making reproductions as in claim 1, wherein said thermoadhesive material having thermoadhesive property is selected from benzoic acid, sebacic acid, phthalic anhydride, cinnamic acid, maleic anhydride, benzotriazole, p-dimethylaminobenzaldehyde, benzoin,

dextrose, acetanilide, vanilline, methylhydroquinone, 2,4- dihydroxybenzophenone, and B-naphthol.

7. The process for making reproductions as in claim 1, wherein said powder development for the image receiving sheet is conducted by a powdered developer capable of attaching to itself said thermoadhesive material in its molten state.

8. The process for making reproductions as in claim 1, wherein said powder development for the image receiving sheet is conducted by a powdered developer coated or mixed with a powdered solid surface active agent.

9. The process for making reproductions as in claim 1, wherein said surface active agent is selected from succinic acid, alkylester sulfonate, alkylbenzene sulfonate, sorbitan alkyl ester, long-chain quaternary ammonium salt, and polyoxyethylene sorbitan alkyl ester.

References Cited UNITED STATES PATENTS FOREIGN PATENTS Great Britain.

WILLIAM D. MARTIN, Primary Examiner.

l EDWARD J. CABIC, Assistant Examiner.

US. Cl. X.R. 

